|posted: 1/9/2004 at 2:32:35 PM ET|
Improvisation is composing simultaneously. (making it up as you go) This is usually based on a given chord progression. It is most common in the jazz style, but is present in all "romantic" styles.
Particualarly in the baroque era.
Syncopation is a term that refers to rhythms that accentuate the "up-beat". It is common in all modern styles, especially jazz. Ragtime and Jazz influenced other classical composers (especially the french) in the early part of this century. Syncopation is also a major part of the African rhythm tradition.